1. Field of the Invention
The present invention relates to a substrate processing apparatus using a neutralized beam, and more particularly, to a substrate processing apparatus using a neutralized beam thereby maintaining a direction of propagation of an ion source for generating ions and a surface of a substrate in respective positions such that they are perpendicular to each other, and a method thereof.
2. Description of the Related Art
Plasma processing apparatus are commonly used in dry etching processes and in physical or chemical vapor deposition processes. In the plasma processing apparatus, a high-frequency power is applied to a chamber, and, at the same time, reaction gases are supplied into the chamber, so that the reaction gases are dissociated in the chamber to excite plasma by means of glow discharge. Here, ions generated from the plasma are used to perform substrate processing.
Meanwhile, integrated circuit design rules have recently been reduced down to 0.1 μm, or less, as semiconductor devices continue to become more highly integrated. As a result, in order to obtain such hyperfine semiconductor devices, processing conditions of the semiconductor processing apparatus have become more critical. Also, performance of the plasma processing apparatus continues to be improved. Such improvements have been primarily obtained through the-techniques of increasing plasma density or equalizing plasma distribution.
However, irrespective of the manner in which the performance of the plasma is improved, the plasma has associated specific limitations on basic physical properties thereof. Namely, since the plasma includes charged ion particles, the ions can cause various problems during a process, such as transforming a specific material layer into an amorphous layer, changing a chemical composition of a surface layer of a substrate, generating a dangling bond in a surface layer of a substrate, and causing charge-up damage to an insulating layer of a gate.
To solve these problems, a semiconductor processing apparatus using a neutralized beam has been introduced. Namely, a substrate is processed by neutralizing ions generated from the plasma and directing the ions to a surface of a substrate. In different methods of neutralizing ions, the ions can made to collide with neutrons, the ions can be made to collide with electrons, and the ions can be made to collide with a metallic substrate.
A technique that employs a metallic substrate for neutralizing ions is disclosed in U.S. Pat. No. 4,662,977, where the metallic substrate is referred to as a neutralizer plate. The angle of the neutralizer plate is controlled, so that the ions can be directed to the substrate by deflecting the ions at a predetermined angle with respect to a scanning direction.
When the collided ions are directed to the substrate using the neutralizer plate, however, the angle between a plasma source and the substrate is to be inclined at an angle of the collision. However, it is difficult to maintain such an inclined angle at the time of manufacturing or managing the apparatus. In addition, since the plasma source is inclined, the path of the ions can be altered depending on the plurality of incidence positions. This can lead to a reduction in incidence uniformity.